This is a huge and crazy idea that would rework the entire hp system, so I know it's probably not going to be a thing. I was just looking at the hp stuff in the dev log that just got posted and had this idea.
I don't really like how everything in the game deals the same amount of damage to you. It's just weird that touching a little purple guy deals the same damage to you as you being blasted with a laser by The Wall. I think it would be cool if instead of having a specific number of hp, you could have an hp bar, where increasing your total hp would make the bar lengthen, and different attacks from different enemies would make your health bar go down different amounts, the smallest enemies dealing the smallest damage, and the largest enemies dealing the largest damage. This also makes giving enemies DOT effect attacks much less devastating and more possible.
Having hearts in the game as pickups to restore your health doesn't really make sense in a bacteria game, so I thought if instead of hearts, you could pick up clumps of ATP that would do the same thing as hearts. Different sized clumps of ATP could restore your health by different amounts. This makes sense to me because the pathogen could use the large amount of stored energy to quickly regenerate their body. I know ATP can't really be stored, no less in clumps, but this is a game with a bacteria who shoots lasers and basically becomes Thor, so I don't think it's a huge problem.
Armor could also be reskinned to Chitin, which would appear as differently sized plates of hard armor-like membrane. This would work exactly the same way as it does now, by adding temporary HP, but now it would be in the form of a white extension to your hp bar. Different sized plates of Chitin would give your different amounts of temporary armor.
If you guys have an idea for something else that would make more sense instead of clumps of ATP, let me know. Just let me know what you all think 